Global Patent Index - EP 0136785 A1

EP 0136785 A1 19850410 - Position control apparatus for controlling positions of rotary heads with respect to a recording medium.

Title (en)

Position control apparatus for controlling positions of rotary heads with respect to a recording medium.

Title (de)

Gerät zur Positionierung von rotierenden Köpfen relativ zu einem Aufzeichnungsträger.

Title (fr)

Appareil de contrÔle de la position de têtes rotatives par rapport à un milieu d'enregistrement.

Publication

EP 0136785 A1 19850410 (EN)

Application

EP 84305278 A 19840803

Priority

JP 14214483 A 19830803

Abstract (en)

An apparatus for controlling the position of the rotary heads (HA-HD) with respect to the recording medium (12) comprises a pulse generating circuit and piezo-electric head displacing mechanisms (90A-90D). The pulse generating circuit outputs a signal with phase and pulse width corresponding to a recording or reproducing period in which one of the rotary heads records or reproduces a signal. To reduce wear, the head displacing mechanism provided with each rotary head separates the non-active heads from the recording medium. Means are also described to compensate for changes in the response of the piezo-electric plates due to age and temperature variations.

IPC 1-7

G11B 5/53; G11B 15/14

IPC 8 full level

G11B 5/54 (2006.01); G11B 5/53 (2006.01); G11B 5/588 (2006.01); G11B 15/14 (2006.01); G11B 15/61 (2006.01); G11B 20/22 (2006.01); G11B 21/12 (2006.01); G11B 21/18 (2006.01); H01L 41/09 (2006.01)

CPC (source: EP US)

G11B 5/531 (2013.01 - EP US); G11B 15/14 (2013.01 - EP US); G11B 15/61 (2013.01 - EP US); G11B 20/22 (2013.01 - EP US); G11B 21/12 (2013.01 - EP US); G11B 21/18 (2013.01 - EP US); H10N 30/101 (2024.05 - EP US)

Citation (search report)

  • [AP] FR 2536893 A1 19840601 - VICTOR COMPANY OF JAPAN [JP]
  • [A] PATENT ABSTRACTS OF JAPAN, vol. 7, no. 113, 18th May 1983; & JP-A-58-32226 (SANYO DENKI K.K.) 25-02-1983
  • [A] PATENT ABSTRACTS OF JAPAN, vol. 6, no. 18, 2nd February 1982; & JP-A-56-140525 (MATSUSHITA DENKI SANGYO K.K.) 02-11-1981
  • [A] PATENT ABSTRACTS OF JAPAN, vol. 6, no. 92, 29th May 1982; & JP-A-57-27424 (MATSUSHITA DENKI SANGYO K.K.) 13-02-1982

Designated contracting state (EPC)

DE FR GB

DOCDB simple family (publication)

EP 0136785 A1 19850410; EP 0136785 B1 19880615; DE 136785 T1 19850814; DE 3472179 D1 19880721; JP S6032110 A 19850219; US 4581662 A 19860408

DOCDB simple family (application)

EP 84305278 A 19840803; DE 3472179 T 19840803; DE 84305278 T 19840803; JP 14214483 A 19830803; US 63628284 A 19840731